71 Chevy truck alternator bracket problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

prateroad · 05-23-2025, 11:53 AM

First off I've never had a problem with these brackets before. I thought mine was in a crash or something and i bought a used one off fleabay and it's the same alignment problem. pics tell the story. Thinking of putting a C50 bracket on but thinking belt will rub ps hose. It gets somewhat better when alternator is tightened but still out some. TIA

54blackhornet · 05-23-2025, 01:06 PM

I have one off a 71 350 you can have for shipping..jack

weq92f · 05-23-2025, 01:18 PM

.

If this is the bracketry you've mounted, I can't see much if any user error that would cause the alt pulley to be so far off. Appears as though you've got it mounted correctly so all indications are that it's either the wrong bracket or it's bent up a bit. If you articulate the alt to where the top mounting ear is nearly straight up, does that change anything?

-Kevin

72c20customcamper · 05-23-2025, 04:00 PM

Quote:

Originally Posted by 54blackhornet

I have one off a 71 350 you can have for shipping..jack

If Prateroad doesn’t want it I’m in need of one for my 72 it has a later model setup on it and I want to go back to original

**1970cstblazer** · 05-24-2025, 07:16 AM

Common mistake for these brackets is for the upper bracket to be mounted on the wrong side of the upper alternator mounting ear. Seen it here a lot even by the top restorers.

**70STOVEBOLT** · 05-24-2025, 09:32 AM

The alternator pulley looks incorrect to me

**Steeveedee** · 05-24-2025, 12:27 PM

Quote:

Originally Posted by 70STOVEBOLT

The alternator pulley looks incorrect to me

I think you're right. Shouldn't the pulley be right at the fan, not spaced out?

**70STOVEBOLT** · 05-24-2025, 01:15 PM

That is what I was looking at.

RustyPile · 05-24-2025, 09:12 PM

An incorrect pulley won't cause a misalignment of the alternator.. I suspect something is causing the bracket to sit at an angle. Perhaps a missing (or extra) spacer or bracket is causing the misalignment.

**70STOVEBOLT** · 05-25-2025, 12:52 PM

I thought the issue was pulley misalignment, didn’t realize it was the bracketry that was misaligned.

**Steeveedee** · 05-25-2025, 12:53 PM

I was thinking that the angle of the alternator was an artifact of the camera.

**pjmoreland** · 05-25-2025, 04:18 PM

Is the front surface of the head machined, or is it a rough cast surface? I'm wondering if these are earlier heads that someone drilled accessory holes in for the alternator.

prateroad · 06-02-2025, 10:51 PM

Quote:

Originally Posted by 54blackhornet

I have one off a 71 350 you can have for shipping..jack

Well, I bent the bracket with a tool bar and it lines up now. I do need the alternator if you still have it. The one in pic is off a C50 Chevy and it won't work.

05-23-2025, 11:53 AM	#1
prateroad Registered User Join Date: Sep 2019 Location: Dade City Posts: 107	71 Chevy truck alternator bracket problem First off I've never had a problem with these brackets before. I thought mine was in a crash or something and i bought a used one off fleabay and it's the same alignment problem. pics tell the story. Thinking of putting a C50 bracket on but thinking belt will rub ps hose. It gets somewhat better when alternator is tightened but still out some. TIA Attached Images

05-23-2025, 01:06 PM	#2
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,481	Re: 71 Chevy truck alternator bracket problem I have one off a 71 350 you can have for shipping..jack __________________ 71 C-20 07 Magnum RT AWD

05-23-2025, 01:18 PM	#3
weq92f Registered User Join Date: Oct 2016 Location: Dallas Texas Posts: 3,850	Re: 71 Chevy truck alternator bracket problem . If this is the bracketry you've mounted, I can't see much if any user error that would cause the alt pulley to be so far off. Appears as though you've got it mounted correctly so all indications are that it's either the wrong bracket or it's bent up a bit. If you articulate the alt to where the top mounting ear is nearly straight up, does that change anything? -Kevin Attached Images __________________ 67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold

05-24-2025, 07:16 AM	#5
1970cstblazer All stock and staying that way Join Date: Jul 2003 Location: Elkland, PA Posts: 2,501	Re: 71 Chevy truck alternator bracket problem Common mistake for these brackets is for the upper bracket to be mounted on the wrong side of the upper alternator mounting ear. Seen it here a lot even by the top restorers. __________________ 1970 K/5 Blazer CST 4WD, TOTM winner December 2024! Medium Bronze poly, 93k ACT. miles, 350, 4 speed, rear positraction, 16.5" x 8.25" HD Kelsey Hayes wheel option, tilt, tach, vacuum, AM/FM, manual throttle...Dad ordered and purchased new 4/70. Frame off restored 1970 K20, To be a clone of my Grandfather's K20, Dark Blue poly, 350, 4 speed, 16.5" X 8.25" Kelsey Hayes wheel option, tilt, tach, vacuum, AM radio. Latest project truck 1972 Cheyenne Super 20 2WD, Dark Blue/White, 90K ACT. miles, 402, TH400, 4.10 open, tilt, tach, vacuum, A/C, AM/FM, manual throttle.. A mostly original paint never rusted Texas survivor... 2017 Sierra 1500 SLT 4WD, Black, 51k miles, 5.3, 6L80E, 3.42 LS, 20" polished wheels, everything but moonroof and 6.2... 2019 Canyon SLT 4WD, White, 71k miles, 3.6, 8L45, 3.23 LS, 18" wheels

05-24-2025, 09:32 AM	#6
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 7,066	Re: 71 Chevy truck alternator bracket problem The alternator pulley looks incorrect to me __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

05-24-2025, 01:15 PM	#8
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 7,066	Re: 71 Chevy truck alternator bracket problem That is what I was looking at. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

05-24-2025, 09:12 PM	#9
RustyPile Registered User Join Date: Dec 2017 Location: Elkhart, Texas Posts: 2,108	Re: 71 Chevy truck alternator bracket problem An incorrect pulley won't cause a misalignment of the alternator.. I suspect something is causing the bracket to sit at an angle. Perhaps a missing (or extra) spacer or bracket is causing the misalignment.

05-25-2025, 12:52 PM	#10
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 7,066	Re: 71 Chevy truck alternator bracket problem I thought the issue was pulley misalignment, didn’t realize it was the bracketry that was misaligned. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

05-25-2025, 12:53 PM	#11
Steeveedee Ram-A-Lam-A-Ding-Dong Join Date: Jan 2013 Location: Simi Valley, CA Posts: 11,903	Re: 71 Chevy truck alternator bracket problem I was thinking that the angle of the alternator was an artifact of the camera. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

05-25-2025, 04:18 PM	#12
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 7,025	Re: 71 Chevy truck alternator bracket problem Is the front surface of the head machined, or is it a rough cast surface? I'm wondering if these are earlier heads that someone drilled accessory holes in for the alternator.



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